In a farmer's field on Denman Island, a pile of plastic baskets, rope, netting and buoys stands as tall as Dorrie Woodward. It's all marine debris that has been collected from the beaches around the northern Gulf island.

"Most of what you see here, unfortunately, is from the shellfish industry. You don't see a lot of water bottles or chip bags," said Woodward, co-chair of the Association for Denman Island Marine Stewards.

"Over 90 per cent of what we do collect, primarily from the western shore of Denman, is debris from the industry."

The volunteer group has organized a cleanup of the beaches of the island each year for more than a decade.

It has also long been calling on the growing shellfish industry to do more to get a handle on debris that breaks free from tenures.

"It's a plastic intensive and plastic dependent industry," Woodward said. "Nothing is tagged, so the moment it breaks loose, it has no attachment to that individual, so no one is responsible."

Shellfish growers in Baynes Sound operate using rafts on the water and and netting along the shoreline. (Megan Thomas/CBC)

Baynes Sound, a waterway that slips between Denman Island and Vancouver Island, has become one of the most active shellfish growing areas in the province.

"When it was originally zoned within the Islands Trust for oyster growing, it was a very low-key, non-invasive kind of thing where young oysters were set out on the stones and later collected," Woodward said.

"It evolved and with that escalation and intensification came animosity."

Despite tensions between those who live along the sound and the industry, there has been a step towards better co-operation this year.

Industry pitches in

Across Baynes Sound in the hamlet of Royston, Darlene Winterburn carefully steps along the rocky beach.

The executive director of the B.C. Shellfish Grower's Association says individual companies already work to remove debris that breaks loose from their tenures and help dispose of it or recycle and reuse it.

But this year, the shellfish industry has agreed to help out with the annual cleanup organized by people on Denman Island.

Plastic oyster trays that break loose from shellfish growing operations collected by volunteers during a cleanup day on the Vancouver Island side of Baynes Sound. (Fisheries and Oceans Canada)

They have teamed up with staff from Fisheries and Oceans Canada, and other volunteers, to comb the shores on the Vancouver Island side of Baynes Sound.

Winterburn admits marine debris is a challenge for shellfish growers.

"The unfortunate reality is that some of our industry debris does blow on shore," she said.

"Ropes go through a lot of stress. You get the winds that will take some stuff away. It's just, unfortunately, the environment in which we work."

The marine stewards on Denman Island also worry about what happens when plastic debris starts to break down in the marine environment.

Chris Marrie, a senior shellfish biologist with Fisheries and Oceans Canada, helped organize more cleanup events this year along Baynes Sound. (Megan Thomas/CBC)

"Here in Baynes Sound, some scientists recently have said it is a hot spot for microplastics and the principal thing is fibre, which often comes from laundry, but it also comes from just so much rope and netting that also breaks up."

"The biggest things that we have learned are contributing to microplastics are things like little bubbles that they put in facial scrubs and dishwasher cleansers, because they are immediately going into the water, and they are immediately there as microplastics," Winterburn said.

"Over a very long period of time, of course, if an oyster tray is there, it's going to break down. But it's going to take a long time."

Winterburn says shellfish growers also have a vested interest in working to resolve the problem.

"Water quality is hugely important to us. Our industry is entirely dependent on it."

Industry oversight

Fisheries and Oceans Canada is making the issue of shellfish aquaculture debris a priority, says Chris Marrie, a senior shellfish biologist with the agency.

"We know that debris is a big issue and we know that there is a lot of public concern over it, and obviously we are concerned as well because we don't want plastic in the ocean."

In the past year, DFO has conducted joint cleanup events with the shellfish industry in eight of the most active shellfish aquaculture areas in B.C.

People on Denman Island say 90 per cent of the marine debris they collect on the beaches comes from shellfish growing operations. (Megan Thomas/CBC)

The agency has also formed a working group with the industry and the provincial government to explore things such as stronger, more durable flotation systems that are less likely to blow apart during storms.

It also has enforcement tools at its disposal — preventing aquaculture refuse from entering the environment is a condition of licence for farm operators.

But Marri says the focus is on prevention, rather than enforcement prosecutions that can be long and costly.

Cleanup wrapping up

This weekend, all of the marine debris gathered on both sides of the sound will be sorted and disposed of or recycled.

Dorrie Woodward says the extra help to clean up the shoreline this year is appreciated.

But the marine stewards on Denman Island also hope the spirit of co-operation will lead to stronger monitoring of the industry.

"The solution to this is not volunteer effort. There has to be a system, which volunteers would augment and support, and that is what is missing here," Woodward said.

"The beach, for us, is part of why we came to live in this community, as it would be for anybody. It's where we bring our children and our grandchildren and everything else."